1. Drying treatment
(1) The plated parts should be dried before being dipped in zinc. Place the plated parts that have been treated with plating flux next to the zinc pot, and use the residual heat from the zinc pot to dry the plated parts to remove the plating flux from the surface of the plated parts. The moisture content of the agent should be basically evaporated.
(2) After the plated parts are dried, immersion plating should be carried out immediately. They should not be left in natural air for a long time to cause the plating flux to fail or the salt film to be oxidized, which will affect the quality of galvanizing and increase the cost.
2. Operation methods and steps of hot dip galvanizing
(1) Operators should be fully prepared before galvanizing. Lifting and transportation equipment, cooling water flow of operating tools, protective facilities, and protective supplies must all be checked and maintained normal.
(2) Operators should pay attention to the temperature of the zinc solution before galvanizing, and control the temperature of the zinc solution according to the thickness, geometry, and material of the plated parts. Generally, the temperature of our photovoltaic brackets is normally controlled between 436°C and 440°C, and production is stopped for insulation. Control between 430℃.
(3) Before immersing zinc parts in zinc liquid, remove the oxide layer on the surface of the zinc liquid. Galvanizing is only allowed to be immersed in the zinc liquid. When the plated parts are immersed in the zinc liquid, they should be immersed at a slow speed or intermittently to prevent explosions. The plated parts should be dipped at a certain tilt angle.
(4) The zinc immersion time should vary according to the material, specifications, and thickness of the plated parts. When the plated parts are immersed in the zinc liquid and the oxide layer has boiled, all reactions have been completed, and the zinc ash can be removed before lifting. The thickness of the workpiece is less than 3mm, the weight of a single frame is less than 1 ton, and the zinc dipping time is about 2 minutes. The thickness of the workpiece is less than 6mm and the length is less than 9m. The zinc dipping time for a single rack or single hanger is less than 1.5 tons: about 1 to 3.5 minutes. The thickness of the workpiece is greater than or equal to 6mm and the length is greater than or equal to 9m. The single frame or single hanging is greater than or equal to 1.5 tons. The zinc dipping time is approximately: 2.5~6min. (Note: For special, special-shaped or special-required plated parts, the immersion plating time should be judged according to the actual requirements.) Since we currently have a single product, we do not have the concept of how much temperature and time is needed to make other workpieces. I will briefly introduce this first. Not much to say.
(5) For hanging products, the vibrator should be turned on when lifting the pot until the zinc liquid level is lifted out to 50cm. Before the plated parts are lifted out of the zinc liquid, the oxide layer and residue on the zinc liquid surface should be removed first, and then the plated parts should be lifted out slowly. The zinc liquid level must be at a certain tilt angle to allow the remaining zinc on the surface to naturally flow into the zinc pot. And remove residual zinc and dripping tumors in time (using iron hooks or bamboo brooms) to ensure the quality of galvanizing.
(6) After the plated parts are plated, they should not stay on the zinc pot for a long time and should be immediately put into the cooling water tank to prevent the zinc layer from oxidizing and affecting the appearance quality. PS: For products with low carbon and low silicon and the workpiece is slightly long and easy to deform, the air cooling time can be extended.
3. Cooling treatment
(1) The cooling water temperature should be kept within 50℃-80℃, and the cooling water pH should be 6.5-9. For workpieces that are easily deformed, the cooling water temperature should be appropriately increased (80-95°C).
(2) When the zinc layer on the surface of the plated part has no obvious fluidity, immediately immerse it in the cooling water tank to make the zinc layer reach its best condition.